Earlier this month, three women held captive for nearly a decade came home. Amanda Barry, Gina DeJesus and Michelle Knight were rescued from a Cleveland basement where they had been held captive since early 2002. The case has generated worldwide attention, some of it fell on the Cleveland Police Department. Officers there had searched in vain over the years for the missing women. Following a case like this for years demands an emotional investment from investigators.

DETECTIVE SERGEANT JOE MATTHEWS: It's the luck of the draw. You know, I mean sometimes you get a police department and a homicide investigator that really takes their time to look through everything, and detail oriented and commit themselves in solving the case. And other times you may get the guy that put your eight hours in, he goes home and forgets about it.

MARTIN: That's Detective Joe Matthews and he is this week's Sunday Conversation. Matthews worked for almost 30 years on one of the most famous cases in the country, the murder of six-year-old Adam Walsh - the son of John Walsh who went on to create "America's Most Wanted." Matthews was taken off the investigation several times when the trail had gone cold. But in the end, he was the one who finally solved the case.

MATTHEWS: You know, in every homicide investigator's career there's always two or three cases that have a impact on him in an emotional and personal and spiritual way. And I think Adam's case had an impact on me. The investigation part of it was like a roller coaster. You know, you had your good, and then bad and the ugly. And at times when you thought things were going really well and then, you know, somebody smack you in the side of the head and you start over.

MARTIN: How do you approach something that is deemed a cold case?

MATTHEWS: In every cold case there is what you call a Hidden Mickey. And a Hidden Mickey is like if you ever go to Disney World, there's Mickey Mouse heads all over the place and people count them, and they see how many they could find. I think the mistakes a lot of investigators make when they do cold cases is they rely on the information that was obtained in the original investigation. In most cases, the answer is in the case file and you just have to redo everything.

Now, in this particular case, I re-interviewed every single witness that was still alive. And that witness led me to other people that were never interviewed.

MARTIN: You talk about how there was no real resolution, there's no closure for the family who goes through something like this. I wonder when this case - when the Walsh case was finally closed after all of those years, after all of the years that you had worked it, what did that resolution to mean for you? What were your own reflections in that moment?

MATTHEWS: It meant very much to me. It meant very much to my family, my children. It meant very much, to say the least, the Walshes and their family. They had a memorial service, just immediate family, and when my wife - it was right before Christmas - she said to Reve, you know, Merry Christmas. And Reve said: This will be the first Christmas that we'll enjoy.

MARTIN: You've been doing this sort of work for decades now and it's tough work. I mean, you're dealing with really horrible events and trauma. I imagine that has to take a toll. Did you ever think about doing something else or taking a break?

MATTHEWS: I think God has given everyone a gift and I couldn't do what you do. Kenny here is holding a mic in front of me, and I couldn't do what he does with all these controls and all that stuff. And I enjoy my work. I love it.

MARTIN: But I imagine even now there are cases you are working - cold cases - that just stay cold.

MATTHEWS: Yeah. Well, I do my best. I've worked cases for years and years and years, so I don't look at any case being totally closed. I just keep going after it and one day you find that Hidden Mickey.

MARTIN: You mentioned that when the case was finally resolved, that it was a relief for your own family. I wonder if you could talk a little bit about how you have to compartmentalize your life, which I imagined you do to certain extent. I mean, were you able when you are working this case, when you are really in it, were you able to put it away when you went home?

MATTHEWS: You know, I think I was. I don't know if my kids and my wife thought I was. I don't really think my kids knew I was a cop until...

(LAUGHTER)

MATTHEWS: ...later on, because I - my wife never wanted me to talk about police work. I never wanted my boys ever to be police officers. I never wanted my daughter to ever date a cop.

MARTIN: Why not?

MATTHEWS: Well, you know, I've been a cop in all my life. I love it. I love it. I wouldn't have done anything in the world other than that. But just so many holidays that I have, you know, haven't been home for - birthday parties. In the middle of Christmas or Thanksgiving, there's a homicide.

When my daughter, she was dating this young man, and I'm saying I got to meet this guy, when are we going to meet him, you know. And she says I want to tell you a little bit about Tom before you meet him, and I hope you're not going to be upset with me. And she said, you know, He's a policeman. And I said, oh, Christina. I said that's not a problem. You know what I mean? And now, she has two beautiful children with him and they're as close to me and my sons' are.

Then my sons started hanging out with him when he was courting my daughter, and two of my three boys are policemen now.

MARTIN: Despite your best intentions.

MATTHEWS: Yeah, but my intentions were honorable. It wasn't like - I love cops, I love the law enforcement industry. I love everything about it. I just didn't think it was fair to, you know, their mates and their families, you know, if they became policeman. But they love it and I am happy for them. And I love them being there.

MARTIN: Detective Sergeant Joe Matthews. He joined us from his home in Davie, Florida. Joe, thank you so much for taking the time. It's been a pleasure.